Precipitants Proteins, specific binding

Sulfation has also been documented in salivary proteins, specifically statherin. The enzymes in saliva are the first wave of the human digestion process and statherin prevents the precipitation of calcium phosphate in the salivary gland and saliva. Since TPST is secreted along with statherin, sulfation plays a role in digestion by binding hydroxylapatite and preventing its precipitation. 

Specific Antibody Determination. Serum samples were prepared from each bleed by centrifugation to remove clotted material. 100 ul of the sera was incubated for 30 minutes with sufficient H-STXOL to provide a ca. 20 fold excess of hapten to the anticipated quantity of specific binding sites. The radioactivity of the protein pellet was determined after ammonium sulfate precipitation. After correction for a small amount of non-specific adsorption of label by control sera proteins the mg/ml of specific antibody in the sample was calculated. 

Among the possible limitations for the use of NMR as a screening tool, the relative insensitivity of NMR as compared with other spectroscopical methods is the more important. This fact imposes the use of high total compound concentration for the ligand molecules and limits the mixture size that can be tested because of compound solubility, protein precipitation and non-specific binding. We shall see in several examples that this limitation turns out to be inherently less important as the use of new probes and higher fields become available, lowering the threshold of sample concentration to be used in these studies. 

The third method that is commonly used relies on the enrichment of methylated sequences. This can be achieved either by 5mC-specific antibodies or by affinity purification using protein domains that specifically bind to 5mC such as MBP or MeCP2. After purification of genomic DNA, the DNA is sheared and precipitated with a specific antibody or purified by immuno-affinity columns and can be analyzed by microarray or NGS. The same procedures can be performed by using a 5hmC-specific antibody that is also... 

Immunoquantitation of poIy(ADP-ribose) polymerase from TCA insoluble fractions. Free and hemocyanin-bound poly(ADP-ribose) polymerase from pig thymus (4) was used to prepare polyclonal antibodies in rabbits. The highest titer was obtained with hemocyanin adducts. With the aid of these antibodies, we have developed a procedure for inununoquantitation of poly(ADP-ribose) polymerase. Amounts of antigen could be determined when the TCA precipitates from cells or tissues were dissolved and applied to nitrocellulose. Antibodies specifically binding to the absorbed antigen were then determined with ( I) protein A. The procedure allowed quantitation of polymerase in the ng range (Fig. 1). Determination of cellular contents required only 10 cells. Recovery of added polymerase was almost quantitative. 

The idea of a hydrophobic film covering the exposed enamel is attractive. In theory a charged head group would bind to the apatite and a hydrophobic tail , such as the hydrocarbon chains found in fatty acids and in phospholipids, would be presented to the saliva. In this way bacterial adhesion and plaque formation could be reduced. The precipitation of specific salivary proteins to produce the acquired pellicle has much the same effect and it is interesting to note that treatment of an apatite surface with hydrophobic salivas reduced the attachment of 5. mutans and other hydrophilic streptococci. 

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